The present invention relates to an emergency stretcher for emergency vehicles, and more particularly, to an emergency stretcher with an improved height adjustment feature.
Typically, an emergency stretcher for emergency vehicles includes a patient litter vertically movable by an X-frame undercarriage that is supported by a wheel base. Examples of such prior art stretchers are disclosed in U.S. Pat. Nos. 4,097,941, 4,192,541, 4,767,148, 5,537,700, and 5,575,026. Although the prior art stretchers have been generally adequate for their intended purposes, they have not been satisfactory in all aspects.
For example, some of these prior art X-frame undercarriages include a releasable locking mechanism having springs, saw toothed members, levers, and horizontal cross members that are external and exposed underneath the patient litter. In some emergency situation, blood soaking through or around the litter padding may contaminate the exposed parts of the undercarriage making the cleaning of the stretcher more difficult. Additionally, some of these prior art stretchers include crossbars on the X-frame undercarriages for added support strength, but having these crossbars adds further to the cleaning problem.
Furthermore, when a number of ambulances respond to an emergency situation the stretchers from the various unit are often not interchangeable due to the incompatible fastening systems on the cots with some of the responding ambulances. This is a problem in the situations where a unit is the first to respond to a scene to retrieve patients but is block-in by later arriving emergency vehicles. If the securing attachment of the stretcher of the first responding ambulance is incompatible with the securing system of an unblocked ambulance, then the patient will either need to be move to a compatible stretcher or wait until the carrying ambulance is freed from the traffic of emergency vehicles.
Accordingly, there is a need for an emergency stretcher with an improved undercarriage that does not have an exposed releasable locking mechanism for vertical height adjustment, does not require crossbars, and has a fastening arrangement that makes it universal with a majority of the cot fastening systems carried on emergency vehicles.
This need is met by the present invention wherein a stretcher comprises, generally, a roller base, a scissor-type lift frame having a lower end rotatably connected to the base, a tubular undercarriage rotatably and slidably connected to an upper end of the frame, a foldable patient support positionable over the undercarriage, a soft, foldable cushion positionable over the patient support and connected thereto to prevent disassociation therefrom, and first and second side-arm supports rotatably connected to the undercarriage.
The wheeled base is rectangular and supports caster wheels at its comers and includes an attachment which permit the stretcher to be secured within conventional ambulances. The lift frame includes a pair of fixed-length leg members and a pair of telescoping variable-length leg members, both of which are rotatably connected to the wheeled base. One of each pair of the leg members is connected to one another at their respective mid-sections by a joint, and is rotatable with respect to one another along an axis of the joint, which is offset from the leg member""s central axes. This allows the leg members to be aligned with one another when the frame is fully collapsed. The variable-length leg members may include gas-charged cylinders therein to assist in extending the lift frame and in raising the stretcher thereby.
The undercarriage includes first and second longitudinal frame members and first and second movable end extensions. The upper ends of the fixed-length members of the lift frame are rotatably connected to the undercarriage, whereas the upper ends of the variable-length members of the lift frame are slidably, as well as rotatably, connected to the undercarriage. A securing device is provided internally to the longitudinal frame members, wherein a pair of securing bars are slidably positioned therein. Each securing bar has one or more recesses spaced there along which is engaged by one of a pair of latches to lock the stretcher at a predetermined height. Each latch is disengaged from the recess of the slidable securing bar by either one or two thumb triggers, located at one of the movable end extensions. Both movable end extensions of the stretcher can be rotatably adjusted from a planar position, to a beveled position and to a dropped position by an associated end release lever.
The patient support and the cushion affixed thereto are also adjustable in thirds and the rigid support includes a mechanical or gas-charged cylinder to assist lifting. Preferably, these components have waffle-type engagement ends to permit articulatable attachment of the three pieces. The side-arm supports rotate about an axis which is offset from the axis of the longitudinal frame members, thereby providing 180 degrees rotational freedom of the side-arm supports from a vertically-up position to a vertically-down position.
In accordance with one embodiment of the present invention, provided is an emergency stretcher, comprising a vertically adjustable wheeled undercarriage having a tubular frame member providing a cavity; an articulatable patient support mount to the undercarriage; and a securing device accommodated within the cavity of the tubular frame member to releasably arrest vertical movement of the patient support by the undercarriage.
In accordance with another embodiment of the present invention, provided is an emergency stretcher, comprising a vertically adjustable wheeled undercarriage having opposed first and second longitudinal frame members each having a proximate end and a distal end, the undercarriage includes a first movable end extension rotatably mounted at the proximate end of each the longitudinal support members, and a second movable end extension rotatably mounted at the distal end of each the longitudinal support members; an articulatable patient support provided on the undercarriage; and a securing device mounted to the undercarriage to releasably arrest vertical movement of the patient support by the undercarriage.
In accordance with another embodiment of the present invention, provided is an emergency stretcher, comprising a vertically adjustable wheeled undercarriage having opposed first and second longitudinal frame members each having a proximate end, the undercarriage includes a first movable end extension rotatably mounted at the proximate end of each the longitudinal support members, the first movable end extension being positionable in at least two positions; an articulatable patient support provided on the undercarriage; a securing device mounted to the undercarriage to releasably arrest vertical movement of the patient support by the undercarriage; and at least one release flipper mounted to the first movable end extension and operational connected to the securing device such that depressing the at least one release flippers will release the securing device in the at least two positions, thereby permitting the vertical movement of the patient support by the undercarriage.
Other objects of the present invention will be apparent in light of the description of the invention embodied herein.